Ceramic ware deburring machine and dressing heads

ABSTRACT

Ceramic ware rotating face down on a vertical axis is raised into engagement with a dressing head provided with a downwardly extending leg having a spring pressed arm inclined downwardly away from its lower end. A horizontal pivot connects the upper end of the arm to the leg in a position allowing the arm to swing in a vertical plane that is generally radial to the axis of rotation of the ware. The arm carries a tool bit that is pivoted to the arm on an axis parallel to the arm pivot. The bit has a lower ware-contact edge extending substantially parallel to the vertical plane of the arm. When rising rotating ware engages this contact edge and lifts the bit, the bit will move radially of the ware and also turn on its own pivotal axis to conform to the engaged surface of the ware. Any burrs on the ware that strike the bit will be knocked off.

United States Patent Haber Feb. 15,1972

[54] CERAMIC WARE DEBURRING MACHINE AND DRESSING HEADS [72] Inventor: Arno Haber, 60l5 Fifth Avenue, Pittsburgh, Pa. 15232 [221 Filed: A m 27,1970

21] Appl.No.: 32,108

52] user ..l25/l0,51/l6l,5l/227R [51] Int. Cl. .1324!) 5/36, B28d H16 [58] FieldofSearch ..'......5l/l6l; 125/10 [56] References Cited UNITED STATES PATENTS 2,468,404 4/1949 9 Miller ..51/5

FOREIGN PATENTS OR APPLICATIONS 350,855 3/1922 Germany ..5l/l6l Primary Examiner-Harold D. Whitehead Attorney-Brown, Murray, Flick & Peckham ABSTRACT Ceramic ware rotating face down on avertical axis is raised into engagement with a dressing head provided with a downwardly extending leg having a spring pressed arm inclined downwardly away from its lower end. A horizontal pivot connects the upper end of the arm to the leg in a position allowing the arm to swing in a vertical plane that is generally radial to the axis of rotation of the ware. The arm carries a tool bit that is pivoted to the arm on an axis parallel to the arm pivot. The bit has a lower ware contact edge extending substantially parallel to the vertical plane of the arm. When rising rotating ware engages this contact edge and lifts the bit, the bit will move radially of the ware and also turn on its own pivotal axis to conform to the engaged surface of the ware. Any burrs on the ware that strike the bit will be knocked off.

13 Claims, 13 Drawing Figures PATENTEDFEB 15 I972 3.641.991

SHEET 1 OF 7 ATTORNEYS.

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PATENTEDFEB 15 I972 3.641.991

SHEET 7 [IF 7 w ARM? HABfR 19) ATTOR/VEVJ.

CERAMIC WARE DEBURRING MACHINE AND DRESSING HEADS In US. Pat. No. 2,468,404, a machine is shown for dressing pottery ware, the purpose being to remove the burrs or marks left on the bottom of the brim or skirt of the ware by the sagger pins during firing. These burrs not only form unacceptable projections on the ware, but they usually are sharp and can cut the fingers if not removed. In the patented machine, rotating ware is raised against blades which the burrs strike as the ware rotates. Although the blades can be adjusted along horizontal arms, for any given position they must be rigidly connected to the arms. They do not move across the ware as it moves upwardly, so a special blade shape is required for each type of ware. Also, in view of the fact that ware often varies in shape slightly from piece to piece, there will be many pieces of ware that will not engage the blades correctly but will engage one corner or the other of a blade which will then cut into the ware rotating against it. Also, the blades shown in the patent are completely unsuited for ware that has a lip around its edge making an angle with the adjoining area of the ware. Moreover, if a piece of ware happens to lift the blades slightly, which can be done because their supporting arms are pivoted, the upper or inner corners of the blades then will cut into the ware. Consequently, much ware can be ruined by attempting to dress it in the patented machine.

It is an object of this invention to provide a deburring machine with dressing heads that are self-adjusting so that theywill not damage ware even though all of the pieces are not uniform. Another object is to provide a dressing head suitable for ware provided with an encircling lip. Further objects are to provide a machine in which the dressing heads can be adjusted manually into the most desirable positions with a minimum amount of effort, in which the deburring bits are quickly replaceable without the use of tools, and in which the bits are knocked out of the way by a broken piece of ware before damage to the machine can occur. An additional object is to provide a machine that will be stopped automatically if a broken piece of ware strikes a bit with objectionable force.

The preferred embodiment of the invention is illustrated in the accompanying drawings, in which FIG. 1 is a fragmentary side view of my deburring machine;

FIG. 2 is an enlarged horizontal section taken on the line II-IIofFIG.1;

FIG. 3 is an enlarged side view of two of the dressing heads in operative position and illustrating the dressing of two different types of ware;

' FIG. 4 is a further enlarged front view of one of the dressing heads;

FIG. 5 is a fragmentary plan view thereof;

FIG. 6 is a fragmentary rear view of the dressing head;

FIG. 7 is a view of the outer end of the dressing head;

FIG. 8 is a view of its inner end; and

FIGS. 9 to 13 are views of a second dressing head corresponding, respectively, to FIGS. 4 to 8.

Referring to FIG. 1 of the drawings, an endless horizontal conveyor 1 carries ceramic ware 2 face down to a dressing station where the ware is centered over a rotatable lifting head 3 v by means of a set of pivoted centering pins 4 of well known construction and operation. The lifting head is on the upper end of a vertically guided stem 5, the lower end of which rests on one end of a lever 6. The opposite end of the lever is pivoted on a horizontal axis. The free end of the lever carries a roller 7 that rests on a continuously rotating cam 8, by which it is alternately raised and lowered. The lifting head lifts the ware from the conveyor into engagement with a chuck 9 on the lower end of a vertically movable shaft 10 journaled in upper and lower bearings 11 and 12 carried by the frame of the machine. Between the two bearings a gear 13 is rigidly mounted on the shaft and normally meshes with the lower part of a drum gear 14 on another rotatable vertical shaft. The first gear slides up the drum gear as the chuck is raised by the lifting head. The chuck normally is held in its lower position not only by gravity but also by concentric coil springs 15 and 16 that encircle shaft 9 and are compressed between a pair of collars. The lower collar 17 is rigidly mounted on the shaft, but the shaft can slide up and down in the upper collar 18, which can turn with the shaft. Mounted on the upper end of the drum gear shaft is a pulley 20 driven by a belt 21 from another pulley 22 that is rotated periodically by a clutch brake mechanism 23. The latter is driven continuously from its lower end by a variable belt drive 24 driven by an electric motor 25. A piece of ware is raised rapidly by the lifting head into engagement with the chuck 9, which then also is' raised to dressing height, which is the height at which the ware starts to' be dressed or deburred by the dressing heads about to be described. Just before the ware reaches dressing height, the brake at 23 is released and the clutch is engaged to start rotating the chuck at high speed through gears 14 and 13. This of course rotates the ware clamped between the chuck and lifting head. When the rotating ware reaches dressing height, shown in dotted lines in FIG. 1, it is then raised slowly a little further while it is being dressed and then the clutch at 23 disengages and the brake is applied to stop rotation of the chuck. The cam 7 then allows the chuck and lifting head to descend'and the latter deposits the dressed ware on the spaced conveyor belts which carry it to an unloading station. The lifting, rotating and dressing then is repeated on the next piece of ware, all in a period of only a few seconds.

To accomplish the dressing, at least one dressing head is used. Two or more identical dressing heads may be required in some cases, while in others dressing heads of different types may be used on the same ware, as shown in the drawings. The dressing head that will be described first is the one on the right-hand side of FIG. 1 and also in FIGS. 2 to 8. It includes a bracket 28 and a frame 29 that are connected by a bolt 30 and a threaded stud 31. The bolt serves as a pivot between the two parts, and the stud-extends through an arcuate slot 32 in the frame and is screwed into the bracket in order to allow the frame to be tilted at different angles relative to the bracket and then locked. Secured to the bracket is a clamp 33 that is operated by a hand screw 34 for clamping the bracket tightly on a square supporting rod 35, along which the bracket can be adjusted different distances from the chuck. One end of the rod secured to a block 37 provided with a horizontal passage that receives a circular stud 38 projecting laterally from a swivel block 39, in which the chuck shaft rotates and slides. The swivel block is rotatably supportedby the machine frame above it and has one of the studs 38 projecting from each of its four sides as shown in FIG. 2. Beside each stud there is a parallel bar 40 at a higher level. One of these bars is longer than the others and carries a setscrew 41 that can be tightened against the machine frame to keep the swivel from turning. The rod block 37 is provided with a lug 42, in which a screw 43 is threaded. The upper end of the screw engages the lower surface of the adjoining bar 40 of the swivel. By turning the screw, the angle that rod 35 makes with the horizontal can be changed to suit the particular ware being dressed.

Extending downwardly from dressing head frame 29 is a leg 44 that is attached to the frame by a pivot 45 parallel to supporting rod 35. Joined to the upper end of the leg is a U-shape member 46 provided with an upwardly extending stud 47, to which one end of a coil spring 48 is attached. The opposite end of the stud is attached to a tension adjusting screw 49 that passes through the back of the frame. This spring tends to swing the lower end of the leg forward, but a lug 50 at the upper end of the leg seats on the frame to normally hold the leg perpendicular to the frame in operative position. On the other hand, if the lower end of the leg is swung backwardly, as will be described, the spring will hold it in a raised retracted position until it is manually returned to its lower position.

The lower end of leg 44 is provided with a horizontal passage extending through it in the plane of movement of the leg, and this passage contains a pivot pin 51, on the front end of which a short arm 52 is rigidly mounted. The arm normally is inclined downwardly and outwardly away from the leg and chuck. Extending from the lower end of the arm back parallel to the pivot pin is a short stub pin 53, the rear end of which projects into an opening in a yoke 54 that is pivotally mounted on the pivot pin at opposite sides of the leg. The head of the pivot pin is spaced from the yoke, and a coil spring 55 encircling the pin is compressed between the head and yoke to hold stub pin 53in the yoke.

Rotatably mounted on the stub pin is a tool bit 57, which is held between the arm and the yoke. The free end of the yoke extends beyond the stub pin and is pivotally connected to the lower end of an adjusting rod 58, the upper end of which is slidably mounted in the overlying U-shape member 46. A coil spring 59 on this rod is compressed between that member and an adjusting nut 60 on the threaded lower portion of the rod. A collar 61 on the upper end of the rod limits its downward movement. By adjusting the nut, the pressure required to swing the arm and yoke upwardly can be varied. In its lower position, the pivoted bit is held with its contact edge facing downwardly by means of a bit positioner pivotally mounted on stub pin 53. This positioner includes a link 62 provided with a lateral lug 63 overlying the top of the bit. The upper end of the link is adjustably connected by a chain 64 or other flexible element to the overlying member 46.

When a piece of ware is raised to dressing height, referred to before, the brim or skirt of the rotating ware comes into engagement with the contact edge of the bit. All adjustments of the dressing head have already been made so that the bit will engage the ware at the desired point. Since the ware is rotating rapidly, any burrs or pin marks on it that strike the bit will be knocked off. The pin marks often are not spaced uniformly from the edge of the ware, so some of them might miss the bit if it engaged only one limited area of the ware. This does not happen with my dressing head, however, because as the ware rotates it also is raised further. This swings the lower end of arm 52 upwardly and outwardly, thereby causing the bit to slide outwardly over the ware. A spiral path on the brim of the ware is therefore covered by the bit, which will remove any pin marks along that path. As the bit is raised it will turn on its pivot so that its contact edge will remain flat against the ware and not dig into it. The ressure that the bit exerts against the ware is determined by adjustable spring 59. As the ware starts to descend again, the bit moves inwardly back toward the center of the ware and therefore a wide area of the ware is again brought into contact with the bit. Since the bit is yieldingly pressed against the ware by spring 59, variations in the height of the ware during dressing do not cause any trouble. In other words, the bit floats on the ware because the bit is not rigidly mounted but has a knee action mounting.

In case it becomes necessary to replace the bit, the pivot pin 51 is pushed by its head to cause arm 52 to pull stub pin 53 out of the yoke. The yoke then can be rotated away from the pin to allow the bit to be slipped off the pin and replaced by another bit. No tool is required for making this quick and easy change of bits.

If the bit is struck by a broken piece of ware clamped between the lifting head and chuck, the impact will swing the bit and the lower end of the leg up out of the way before damage can occur. Also, it is desirable to mount on the dressing head frame an electric switch 66 that, when open will shut off all of the power to the machine. The switch normally is held closed by an arm 67 secured to member 46 and holding down the spring-pressed button 68 of the switch. When leg 44 is swung back to retracted position, arm 67 is swung forward away from the button. The released button allows the switch to open and shut down the machine so that the broken ware can be removed. A lever or the like can be attached to the upper end of shaft to permit the chuck to be raised to release the broken ware.

The hit just referred to has a straight ware-contacting edge, but such an edge is not suitable where there is a lip or flange on the ware that a corner of the bit could cut into if it approached close to the outer edge of the ware. Such a lip may be formed on a bowl, for example, as shown in FIG. 3. It is at an angle to the adjoining portion of the bowl. To remove any pin marks that may be on or close to the lip, a bit is used that has a convex contact edge. Also, the dressing head that carries this bit is so constructed and arranged that the lip of the ware will first engage the bit and then the bit will travel inwardly, instead of outwardly, over the ware as the ware is raised further. This particular dressing head is disclosed in detail in FIGS. 9 to 13.

In this second dressing head there likewise is a bracket 70 that is clamped onto a square supported rod 71 projecting from one of the studs 38 of the swivel head. Also, like the other dressing head, this one includes a frame 72 connected to the bracket by a lower pivot 73 and by an upper setscrew 74 extending through an arcuate slot 75 in the frame and screwed into the bracket. The upper end of the leg 76 is connected by a pivot 77 to the frame on an axis parallel to the supporting rod 71. A U-shape member 78 joined to the upper end of the leg supports a stud 79, to which one end of a coil spring 80 is attached. The rear end of the spring is attached to an adjusting screw 81 extending through the frame. The leg normally is held perpendicular to the frame by a lug 82 extending from the leg across the top of the frame. The lower end of the leg is provided with a passage in which a pivot pin 83 is slidably a rotatably mounted. The front end of the pin supports an arm 84 that is inclined downwardly and inwardly toward the chuck. The rear end of the pin has a head that is spaced by a coil spring 85 from a yoke 86 pivotally mounted on the pin at opposite sides of the leg. The lower end of the yoke has an opening through it that receives a stub pin 87 projecting rearwardly from the lower end of the arm. The curved bit 88 and a bit positioner link 89 a1'e rotatably mounted on this pin between the arm and yoke. The upper end of the link is adjustably connected by a chain 90 or the like to an overlying member 91 projecting from the U-shape member 78. The upper end of the link also has a screw 92 extending through an arcuate slot 93 in a bracket 94 secured to the top of arm 84. When a nut 95 on this screw is tightened against the bracket, it will lock the bit positioner in any desired position relative to the arm. A fixed position for this curved bit sometimes is desired. The bit is urged downwardly by a coil spring 96 connected at its lower end to 2 lug 97 projecting outwardly from the upper end of the arm. The upper end of the spring is attached to an adjusting screw 98 through the U-shape member 78 above it. The arm can be held in a raised position by screwing a setscrew 99 down against lug 97. This is done when the lip of the ware is narrow so that the bit should not move inwardly across it. At such a time nut 95 can be tightened to hold the bit positioner stationary also.

This dressing head is positioned so that when a rotating piece of ware is raised the curved bit edge will engage the curved lip of the ware. Then as the ware continues to rise, it

will swing arm 84 upwardly and inwardly toward the centerof the ware and this will cause the bit to move inwardly away from the lip a short distance. By mounting this tool and the one first described in the same machine, the entire surface of the skirt of the ware can be covered so that no burrs will be missed. In case a broken piece of ware strikes the bit it can yield because leg 76 can swing on its pivot backwardly to its raised retracted position.

If desired, a device for depositing a lubricating powder on the rotating ware can be supported by one of the studs 38.

I claim:

1. A dressing head for deburring vertically movable ceramic ware rotating face down on a vertical axis in a deburring machine, the head comprising a frame, means secured to the frame adapted to attach 'it to the machine above the ware, a

leg extending down from the frame, an arm inclined downwardly away from the lower end of the leg, a horizontal pivot connecting the upper end of the arm to the leg in a position allowing the arm to swing in a vertical plane generally radial to said vertical axis, a spring urging the opposite end of the arm downwardly, and a tool bit carried by the arm and pivoted thereto on an axis parallel to said pivot, the bit having a lower ware-contact edge extending substantially parallel to said plane, whereby when rising rotating ware engages said contact edge and lifts the bit the latter will move radially of the ware and also turn on its own pivotal axis to conform to the engaged surface of the ware.

2. A dressing head according to claim 1, including means for adjusting the pressure of said spring downwardly on said arm.

3. A dressing head according to claim 1, including flexible means connecting said bit with the frame above it to hold the bit in a predetermined position when said arm is in its lower position.

4. A dressing head according to claim 1, including a bit positioner engaging the bit and pivoted on the same axis, and flexible means connected to said positioner and frame to hold the bit positioner in a predetermined position relative to said arm when the arm is in its lower position.

5. A dressing head according to claim 1, including a pin projecting from one side of said arm and pivotally supporting said bit, and retaining means pivotally supported by said leg and normally holding the bit on said pin, said horizontal pivot being manually movable axially to move said arm and pin away from said retaining means to permit the bit to be removed from the pin.

6. A dressing head according to claim 5, in which said retaining means is a yoke provided with a hole receiving the free end of said pin, the head including a spring on said horizontal pivot urging said arm toward the yoke.

7. A dressing head according to claim 1, including means pivotally connecting the upper end of said leg to the frame on an axis substantially parallel to said vertical plane, a spring normally holding the leg in its down position but permitting it to be swung upwardly to a retracted position if said bit is struck by a broken piece ofware.

8. A dressing head according to claim 7, including an electric switch, and a switch-operating member connected with said leg and normally holding the switch closed, said member being swung away from the switch to permit it to open when the leg is swung up to its retracted position.

9. A dressing head according to claim 4, including means for locking said bit positioner in different selected positions relative to said arm.

10. A dressing head according to claim 9, in which said lastmentioned means include an arcuately slotted member secured to said arm, and a fastener extending through the slotted member from the upper end of said bit positioner, the fastener being formed to be tightened against said member.

1 l. A ceramic ware deburring machine, comprising a lifting head rotatable on a vertical axis, a vertically movable chuck spaced above said head, a conveyor carrying ware face down into a position between said head and chuck, means for raising said head to lift the ware into engagement with the chuck, means for rotating the chuck to rotate the ware as it continues to rise, and a dressing head supported above the chuck including a supporting member extending outwardly beyond the chuck, a tool bit, means pivotally connected with said member to support the bit for movement across the ware in a direction generally radial to the chuck as the bit is raisedby rising rotating ware, and a pivot connecting the bit with said last-mentioned means to allow the bit to rock so that it will conform to the surface of ware engaged by it.

12. A machine according to claim 11, in which said lastmentioned means include a normally inclined arm pivoted at its upper end on a horizontal axis substantially perpendicular to a vertical plane generally radial to said chuck, and said pivot is at the lower end of said arm and substantially parallel to said horizontal axis.

13. A machine according to claim 11, including means for adjusting said last-mentioned means along said supporting member to vary the distance between the tool bit and the axis of the chuck. 

1. A dressing head for deburring vertically movable ceramic ware rotating face down on a vertical axis in a deburring machine, the head comprising a frame, means secured to the frame adapted to attach it to the machine above the ware, a leg extending down from the frame, an arm inclined downwardly away from the lower end of the leg, a horizontal pivot connecting the upper end of the arm to the leg in a position allowing the arm to swing in a vertical plane generally radial to said vertical axis, a spring urging the opposite end of the arm downwardly, and a tool bit carried by the arm and pivoted thereto on an axis parallel to said pivot, the bit having a lower ware-contact edge extending substantially parallel to said plane, whereby when rising rotating ware engages said contact edge and lifts the bit the latter will move radially of the ware and also turn on its own pivotal axis to conform to the engaged surface of the ware.
 2. A dressing head according to claim 1, including means for adjusting the pressure of said spring downwardly on said arm.
 3. A dressing head according to claim 1, including flexible means connecting said bit with the frame above it to hold the bit in a predetermined position when said arm is in its lower position.
 4. A dressing head according to claim 1, including a bit positioner engaging the bit and pivoted on the same axis, and flexible means connected to said positioner and frame to hold the bit positioner in a predetermined position relative to said arm when the arm is in its lower position.
 5. A dressing head according to claim 1, including a pin projecting from one side of said arm and pivotally supporting said bit, and retaining means pivotally supported by said leg and normally holding the bit on said pin, said horizontal pivot being manually movable axially to move said arm and pin away from said retaining means to permit the bit to be removed from the pin.
 6. A dressing head according to claim 5, in which said retaining means is a yoke provided with a hole receiving the free end of said pin, the head including a spring on said horizOntal pivot urging said arm toward the yoke.
 7. A dressing head according to claim 1, including means pivotally connecting the upper end of said leg to the frame on an axis substantially parallel to said vertical plane, a spring normally holding the leg in its down position but permitting it to be swung upwardly to a retracted position if said bit is struck by a broken piece of ware.
 8. A dressing head according to claim 7, including an electric switch, and a switch-operating member connected with said leg and normally holding the switch closed, said member being swung away from the switch to permit it to open when the leg is swung up to its retracted position.
 9. A dressing head according to claim 4, including means for locking said bit positioner in different selected positions relative to said arm.
 10. A dressing head according to claim 9, in which said last-mentioned means include an arcuately slotted member secured to said arm, and a fastener extending through the slotted member from the upper end of said bit positioner, the fastener being formed to be tightened against said member.
 11. A ceramic ware deburring machine, comprising a lifting head rotatable on a vertical axis, a vertically movable chuck spaced above said head, a conveyor carrying ware face down into a position between said head and chuck, means for raising said head to lift the ware into engagement with the chuck, means for rotating the chuck to rotate the ware as it continues to rise, and a dressing head supported above the chuck including a supporting member extending outwardly beyond the chuck, a tool bit, means pivotally connected with said member to support the bit for movement across the ware in a direction generally radial to the chuck as the bit is raised by rising rotating ware, and a pivot connecting the bit with said last-mentioned means to allow the bit to rock so that it will conform to the surface of ware engaged by it.
 12. A machine according to claim 11, in which said last-mentioned means include a normally inclined arm pivoted at its upper end on a horizontal axis substantially perpendicular to a vertical plane generally radial to said chuck, and said pivot is at the lower end of said arm and substantially parallel to said horizontal axis.
 13. A machine according to claim 11, including means for adjusting said last-mentioned means along said supporting member to vary the distance between the tool bit and the axis of the chuck. 